MAINT: Rename chebinterp to chebinterpolation and add test.

* Rename chebinterp to chebinterpolation as suggested.
* Make some fixes to the Chebyshev class function.
* Refactor TestInterpolation.
* Add test for the Chebyshev.interpolation class function.

1 files changed, 25 insertions, 0 deletions

diff --git a/numpy/polynomial/tests/test_classes.py b/numpy/polynomial/tests/test_classes.py
index 46d721df4..2ec8277ff 100644
--- a/numpy/polynomial/tests/test_classes.py
+++ b/numpy/polynomial/tests/test_classes.py
@@ -583,5 +583,30 @@ def check_ufunc_override(Poly):
     assert_raises(TypeError, np.add, x, p)
 
 
+class TestInterpolate(object):
+
+    def f(self, x):
+        return x * (x - 1) * (x - 2)
+
+    def test_raises(self):
+        assert_raises(ValueError, Chebyshev.interpolate, self.f, -1)
+        assert_raises(TypeError, Chebyshev.interpolate, self.f, 10.)
+
+    def test_dimensions(self):
+        for deg in range(1, 5):
+            assert_(Chebyshev.interpolate(self.f, deg).degree() == deg)
+
+    def test_approximation(self):
+
+        def powx(x, p):
+            return x**p
+
+        x = np.linspace(0, 2, 10)
+        for deg in range(0, 10):
+            for t in range(0, deg + 1):
+                p = Chebyshev.interpolate(powx, deg, domain=[0, 2], args=(t,))
+                assert_almost_equal(p(x), powx(x, t), decimal=12)
+
+
 if __name__ == "__main__":
     run_module_suite()